from django.shortcuts import render
from django.shortcuts import render, get_object_or_404
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
from django.core.mail import send_mail
from .models import Post
from .forms import EmailPostForm,CommentForm,SearchForm
from taggit.models import Tag
# 导入Django聚合函数Count
from django.db.models import Count
from django.contrib.postgres.search import SearchVector
# Create your views here.
def post_list(request,tag_slug=None): 
   posts = Post.published.all()
   tag = None
 # 如果请求中有tag_slug，则获取标签并按标签过滤文章数据
   if tag_slug:
 # 获取标签
       tag = get_object_or_404(Tag, slug=tag_slug)
 # 按标签过滤文章
       posts = posts.filter(tags=tag)
   paginator = Paginator(posts, 3)
   page = request.GET.get('page')
   try:
      posts = paginator.page(page)
   except PageNotAnInteger:
      posts = paginator.page(1)
   except EmptyPage:
      posts = paginator.page(paginator.num_pages)
   return render(request,'blog/post/list.html',{'posts':posts,'page':page,'tag':tag})
 # 向模板传递页号数据
def post_detail(request, year, month, day, post):
   post = get_object_or_404(Post, slug=post, status='published',
                           publish__year=year,
                           publish__month=month,
                           publish__day=day)
   comments = post.comments.filter(active=True)                        
   comment_form = CommentForm()   
   new_comment = None
   if request.method == 'POST':
       comment_form = CommentForm(data=request.POST) 
       if comment_form.is_valid():
        new_comment = comment_form.save(commit=False)
        new_comment.post = post
        new_comment.save() 
   else:
      comment_form = CommentForm()    
   post_tags_ids = post.tags.values_list('id', flat=True)
   similar_posts = Post.published.filter(tags__in=post_tags_ids)\
                           .exclude(id=post.id)
   similar_posts = similar_posts.annotate(same_tags=Count('tags'))\
                           .order_by('-same_tags','-publish')[:4]          
   return render(request, 'blog/post/detail.html', {'post': post,'comments': comments,'ne_comment': new_comment,'comment_form': comment_form,'similar_posts': similar_posts})
def post_share(request, post_id):
 # 获取要分享的文章信息
   post = get_object_or_404(Post, id=post_id, status='published')
 # 设置发送状态为未发送
   sent = False
 # 如果请求是POST表示有提交表单
   if request.method == 'POST':
 # 通过EmailPostForm表单类获取请求中的表单数据后保存到form中
      form = EmailPostForm(request.POST)
 # 如果表单数据验证通过则发送邮件并将状态设置为已发送
      if form.is_valid():
        cd = form.cleaned_data
 # 构建请求路径
        post_url = request.build_absolute_uri(post.get_absolute_url())
 # 构建邮件标题
        subject = f"{cd['name']} recommends you read " \
                                f"{post.title}"
 # 构建邮件正文
        message = f"Read {post.title} at {post_url}\n\n" \
                                f"{cd['name']}\'s comments: {cd['comments']}"
 # 发送邮件
        send_mail(subject, message, '1554613108@qq.com',
                                [cd['to']])


 # 发送邮件，稍后完成
 # 发送状态设置为真
        sent = True
   else:
 # 如果表单数据验证未通过将表单设置为空
         form = EmailPostForm()
 # 渲染分享文章模板，并将文章、表单、发送状态信息传递给文章分享模板
   return render(request, 'blog/post/share.html', {'post': post,'form': form,'sent': sent})
def post_search(request):
   form = SearchForm()
   query = None
   results = []
 # 如果请求中有query字段则获取表单中的数据进行处理
   if 'query' in request.GET:
 # 获取表单
     form = SearchForm(request.GET)
 # 如果表单中的数据验证通过，即有效，则获取并处理
     if form.is_valid():
 # 获取搜索内容保存下来
       query = form.cleaned_data['query']
 # 根据标题和正文字段构建搜索向量并生成搜索字段，再根据搜索内容筛选出匹配内容保存
       results = Post.published.annotate(
       search=SearchVector('title', 'body')
       ).filter(search=query)
 # 将搜索结果渲染到搜索模板并返回
   return render(request,
                 'blog/post/search.html', {
                 'form': form,
                 'query': query,
                 'results': results
                })
